Recently, a technology, so-called “microchemical process technology”, of performing chemical reaction in a reaction channel having fine channel sectional area is under development (JP-A-2000-298109 (“JP-A” means unexamined published Japanese patent application)). The “microchemical process technology” is a method of producing or analyzing substances chemically by using chemical and physical phenomena exhibited in microchannel having a width of several μm to hundreds of μm that is formed on a solid substrate for example by micro-processing technology.
Fluids move mostly in laminar flow in microspaces where the Reynolds number is normally lower and are often mixed through an interface by molecular diffusion. In such a microspace where the specific surface area of the interface is larger and the molecule travelling distance can be lowered, the fluids are mixed instantaneously through the interface by molecule diffusion. Thus, it is possible to mix fluids more rapidly and accurately than by turbulent flow mixing with a common macroscale stirrer. In addition, it is also possible to control the flow rate and the reaction time accurately, because the reaction is generally performed in the flow state. It is also possible to control the temperature more accurately, because heat transfer is easier.
However, in conventionally proposed microdevices, it was necessary to isolate a product obtained in a microdevice and supply it into another microdevice, for mixing and reaction of a plurality of fluids in a plurality of phases. In such a case, two microdevices should be connected with a joint for connection. Accordingly, there was limit in reducing the volume of the connection region, and thus, it was difficult to control the temperature and the residence time in the connection region. In particular, such a system cannot be used when a desired product is not obtained selectively in sequential chemical reaction, unless the residence time in the first step before reaction in the next secondary step is, for example, shorter than approximately 0.1 second. For example when halogen-lithium exchange reaction is carried out in such a microreactor (JP-A-2006-241065), the volume of the junction region of the microdevice becomes too large for favorable reaction.
Alternatively, devices containing microchannels produced by laminating glass substrates or metal substrates or those containing the accumulation thereof were studied (JP-A-10-337173 and JP-A-2005-161125). However, with these devices, it was necessary to produce the device once again with significant modification, if there was change in the residence time even in one step of its multistage steps. It is also difficult structurally to control the temperature in each mixing step independently, restricting the scope of its application.